Quantech proposes to develop an interactive computer system capable of assisting statisticians in the design of statistical aspects of phase III clinical oncology trials. The system will advise the user concerning choices of type I error, power, detectable treatment differences and sample size. When exact or approximate formulas aren't available, numerical results will be obtained by computer simulations. The SBIR phase I effort will identify designs in current use for oncology trials, theory for the selection of design parameters, and methods to expedite use of the computer system. Portability across microcomputers and mainframes will also be ensured in phase I. The system's feasibility will be demonstrated by creating a preliminary version. In SBIR phase II, the full set of analytic and simulation procedures as well as convenient methods for command and display will be added to the system while avoiding excessive machine-dependence. By facilitating access to sophisticated methods for the design of trials with failure-time outcomes, the system will have wide commercial applications among those doing clinical research in cancer treatment, basic biomedical researchers, drug companies, as well as engineers doing reliability studies on physical systems.